Put the eggplant in a single layer onto 2 (9 by 17-inch) baking sheets. Brush both sides with 3 tablespoons canola oil and season with salt and pepper. Bake until browned and softened, 10 to 15 minutes.
In a large skillet over medium-high heat, add the remaining 1 tablespoon canola oil and the onions and cook until they soften, about 3 minutes. Add the beef, breaking into pieces with a wooden spoon. Add the garlic, Italian seasoning, 1/2 teaspoon cinnamon, and salt and pepper. Stir in the tomatoes and simmer until it is thick and the flavors have combined, 20 to 25 minutes. Taste and adjust the seasoning with salt and pepper, if needed.
In a small saucepan over medium heat, melt the butter. Whisk in the flour and cook for 2 minutes. Slowly whisk in the milk, season with salt and pepper, and the remaining 1/2 teaspoon cinnamon. Bring it to a simmer, and cook until it is thick, about the consistency of pancake batter.
Put a layer of eggplant into a 9 by 9-inch baking dish. Spread the beef mixture evenly over the top. Put another layer of eggplant on top (reserve the remaining eggplant for Online Round 2 Recipe Eggplant Dip). Pour the bechamel sauce over the top and sprinkle with the cheese. Bake until browned and bubbling, 25 to 30 minutes. Remove from the oven and let rest for 10 minutes. Garnish with the parsley before serving.